I agree that its about getting draft picks and cap flexibility for the Magic, Mick, but I reckon they had a better deal on the table from Houston earlier.
Vucevic MAY become pretty good, but he was only a mid-teens pick, as is Harkless. Afflalo is a nice role player, nothing more. The future picks they get won't be in the lottery with the probable exception of Denver, who might get them a pick in the 12-14 range.
They could have had Kevin Martin for a year to help make the basketball more palatable for fans, trade him for more pieces during the season or even resign him at the end if they want.
Added to that they could have probably had all three of Houston's teen picks in the last draft and other low cost guys with some ability and potential in Patterson, Parsons, Morris and Motiejunas.
On top of that, Houston was reportedly willing to take on most of the Magic's bad salary (Turkoglu, Davis, J-Rich). In the deal it looks like they have just taken they are only getting rid of J-Rich.
In addition, if I'm the Magic, I've been screwed so badly by Howard that the last thing I want to do is help him get what he wants.
Hell, if I were the Magic GM, I'd try to dump him in Charlotte for some of their never ending stream of high draft picks!